From 7db47f8084c176f5944964a768781c952a6a9c92 Mon Sep 17 00:00:00 2001
From: tigercosmos <b04209032@ntu.edu.tw>
Date: Sat, 23 Sep 2017 15:12:35 +0800
Subject: [PATCH] fix #18594: Unnecessarily allocating an error string

---
 components/script/document_loader.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/components/script/document_loader.rs b/components/script/document_loader.rs
index 4a6307667f1..9fe42e30147 100644
--- a/components/script/document_loader.rs
+++ b/components/script/document_loader.rs
@@ -130,7 +130,7 @@ impl DocumentLoader {
     pub fn finish_load(&mut self, load: &LoadType) {
         debug!("Removing blocking load {:?} ({}).", load, self.blocking_loads.len());
         let idx = self.blocking_loads.iter().position(|unfinished| *unfinished == *load);
-        self.blocking_loads.remove(idx.expect(&format!("unknown completed load {:?}", load)));
+        self.blocking_loads.remove(idx.unwrap_or_else(|| panic!("unknown completed load {:?}", load)));
     }
 
     pub fn is_blocked(&self) -> bool {